sébastien galais s. galais, j. kneller, c. volpe and j. gava

The shockwave impact upon the Diffuse Supernova Neutrino

Background

GDR Neutrino, Ecole Polytechnique

Sébastien GALAIS

S. Galais, J. Kneller, C. Volpe and J. GavaPhys.Rev.D81:053002,2010 / arxiv:0906.5294 [hep-ph]

Plan

Diffuse Supernova Neutrino Background (DSNB) Motivations

o Introduction

The neutrino self-interaction The shockwave effects in supernova

o Theoretical Framework

on the fluxes on the events rates

o Results

o Simplified model to reproduce the shockwave effects

Introduction

Introduction Theoretical Framework Results Simplified Model Conclusions

neutrinos

NeutronStar

1. The interaction : neutrinos interact each other giving rise to collective effects.

- J. T. Pantaleone, Phys. Rev. D 46 510 (1992).- S. Samuel, Phys. Rev. 48, 1462 (1993).- G. Sigl and G. G. Raffelt, Nucl. Phys. B 406 423 (1993).- Y. Z. Qian and G. M. Fuller, Phys. Rev. D 51 1479 (1995).- H. Duan, G. M. Fuller, J. Carlson, and Y.-Z. Qian, Phys. Rev. 74, 105014 (2006), 0606616,…

Neutrino-sphere

Core-collapse supernova explosion

99 % of the energy is released by (anti)neutrinos of all flavors (about 1053 ergs for about 10 seconds).

Introduction

neutrinos

NeutronStar

matter

2. The shockwave effects : The shock will modify the density profile and therefore the MSW resonance.

- R. C. Schirato and G. M. Fuller (2002), 0205390.- C. Lunardini and A. Y. Smirnov, JCAP 0306, 009 (2003), 0302033.- G. L. Fogli, E. Lisi, A. Mirizzi, and D. Montanino, Phys. Rev. 68, 033005 (2003), 0304056.- J. P. Kneller, G. C. McLaughlin, and J. Brockman, Phys. Rev. 77, 045023 (2008), 0705.3835.- …

Neutrino-sphere

MSW


Diffuse Supernova Neutrino Background (DSNB)

Supernova explosion

Neutrinos are emitted with a Fermi-Dirac distribution:

• from a localized region.

• during a finite time.


Neutrinos are emitted with a Fermi-Dirac distribution:

• from all directions (past and invisible SN).

• the background is there.

DSNB

Energies are redshifted due the distance between the SN and Earth:

Much progress have been done on its ingredients such as star formation rate. - S. Ando and K. Sato, New Journal of Physics 6, 170 (2004), 0410061- L. E. Strigari, J. F. Beacom, T. P. Walker and P. Zhang, JCAP 0504, 017 (2005), 0502150- C. Lunardini, Astroparticle Physics 26, 190 (2006), 0509233- H. Yüksel and J. F. Beacom, Phys. Rev. 76, 083007 (2007), 0702613)- …


Motivations Numerical simulations are close to the upper limits for relic neutrinos fluxes (Super Kamiokande, LSD).

Detection window for relic neutrinos.


Future observatories should be able to observe these fluxes.

• MEMPHYS: 440 kTon Water Čerenkov detector.Main detection channel:

• GLACIER: 100 kTon liquid argon detector.Main detection channel:

Our aim is to explore:1)the shockwave effects (in the supernova) upon the DSNB.

2)the sensitivity to the oscillations parameters (Hierarchy, 13, phase).

• LENA: 44 kTon scintillator detector.Main detection channel:


• z: redshift• : energy of the neutrino at emission (neutrinosphere)• RSN: core-collapse supernova rate per unit comoving volume• : differential spectra emitted by the supernova

Theoretical framework

Diffuse Supernova Neutrino Background (DSNB) flux at Earth.

Flat universe and ΛCDM model:

ΩΛ=0.7 Ωm=0.3 H0=70 km s-1 Mpc-1


Supernova Rate RSN. Many constraints (Gamma-ray bursts, rest-frame UV, NIR Hα, and

FIR/sub-millimeters observations)

Star Formation Rate (RSF)

Star formation rate RSF from [1], where RSF is divided in three parts.

[1] H. Yuksel, M. D. Kistler, J. F. Beacom, and A. M. Hopkins, Astrophys. J. 683, L5 (2008).

with


The propagation in supernovae

e

e-

NeutronStar

MSW effect interaction Vacuum osc



e

e-

NeutronStar


Hierarchy13



e

e-

NeutronStar


SHOCK

Hierarchy13


Our simulationWe use a 3 flavour code in which we solve the propagation of the amplitudes. We include the interaction (single angle approximation).

J. Gava, C. Volpe, Phys.Rev.D78:083007(2008), 0807.3418.

Inverted hierarchy; 13=9, 23=40

Movies realized by S. Galais.


Synchronized regionBipolar oscillations

Spectral split region


Our simulation

J. Gava, C. Volpe, Phys.Rev.D78:083007(2008), 0807.3418. Movies realized by S. Galais.



Our simulation




Synchronized regionBipolar oscillations

Spectral split region

Our simulation



Shockwave effects in supernovae

E=20 MeV

Evolution of the density profile with time in the MSW region.

1. Before the shock (adiabatic propagation).

Without .

Impact on the probability.


E=20 MeV

2. The shock arrives (non-adiabatic prop.).

Without .






E=20 MeV

3. Phase effects appear.

Without .







Without .

E=20 MeV

4. Post-shock propagation.


3. Phase effects appear.






A complete calculation including the shockwave has been realized.

Now we’re aiming at: seeing its impacts on the fluxes and events rates.

exploring the sensitivity to oscillations parameters: 13, hierarchy.

Normal Hierarchy for .

Inverted Hierarchy for .

+ shock (numerical).

RESULTS: relic electron (anti-)neutrino fluxes

For 13 we have two cases: L and S.

+ no shock (analytical).13 Small.

Results for 13 large are valid for the range:

(Me

V-1 c

m-2 s

-1)

13 Small. + no shock. + shock.

(Me

V-1 c

m-2 s

-1)

Chooz limit Best limit for future facilities

exp window

(argon detector)

exp window

(Čerenkov detector)

Normal Hierarchy for .

Inverted Hierarchy for .


+ shock. + no shock.

Here is plotted the ratio

Shockwave impacts:

• 10-20% effect from numerical calculations.

+ no shock. + shock.NH IH


+ shock. + no shock.


Shockwave impacts:

• 10-20% effect from numerical calculations.

+ no shock. + shock.NH IH

• reduction of the sensitivity to 13.


Water Čerenkov, scintillator detectors and Inverted Hierarchy (with )

Analytical (no shock) Numerical (shock)

Nevents Detection window L L

19.3-30 MeV 0.066 0.078

Argon detectors and Normal Hierarchy

17.5-41.5 MeV 0.074 0.066

DSNB event rates (per kTon per year)

+18%

-11%

• 10-20% variation only due to the presence of the shock.


Water Čerenkov, scintillator detectors

Inverted Hierarchy (with )

Nevents Detection window L (no shock) L (shock) S

19.3-30 MeV 0.066 0.078 0.089

Argon detectors and Normal Hierarchy

17.5-41.5 MeV 0.074 0.066 0.058

• The sensitivity to 13 is reduced.• 10-20% variation only due to the presence of the shock.

-12%

+14%


-26%

-28%


• Loss of the sensitivity to collective effects in the L case.• The sensitivity to 13 is reduced.• 10-20% variation only due to the presence of the shock.

Water Čerenkov, scintillator detectors

Inverted Hierarchy (with shock)

Nevents Detection window L (with ) L (without )

19.3-30 MeV 0.078 0.078

9.3-25 MeV 0.211 0.210

+0%

+0%



What have we learnt?

one should include the shockwave in future simulations because its effects are significant.

To do so, we propose a simplified model to account for these effects.

1. From the numerical evolution of , we extract the 3 times.

ts: shock arrives

tp: phase effects

t∞: post-shock

2. We average the value of in each part because is independent of the energy.

A simplified model to account for the shockwave

This model based upon the general behaviour of the shockwave in supernova to calculate the flux.


Survival probability evolution with times and energy.

A simplified model to account for the shockwave Introduction Theoretical Framework Results Simplified Model Conclusions

Interval 0→ts ts→tp tp→t t→

With 0.5436 0.0634 0.3092 0.2548

Without 0.1611 0.6356 0.3531 0.4835

Times fitting with polynomials functions.

The simulations using these functions reproduce the full calculation to less than 2%.


Conclusions First complete calculation with interaction and shockwave for relic supernova neutrinos.

The shock affects significantly the DSNB fluxes and event rates.

We propose a model that can be used in future calculations to include shockwave effects.

S. Galais, J. Kneller, C. Volpe and J. Gava, Phys.Rev.D81:053002,2010 / arxiv:0906.5294 [hep-ph]


Our predictions for future observatories after 10 years

MEMPHYS, UNO

440 kTon290 < Nevents < 392

LENA


GLACIER


IH

NH

S. Galais, J. Kneller, C. Volpe and J. Gava, Phys.Rev.D81:053002,2010 / arxiv:0906.5294 [hep-ph]

Simplified model VS Numerical calculation


Modification of the parameters

Variation of the cooling time .

Addition of a temporal offset t to ti.

Luminosity decreases like:

Change the arrival time of the shock.

Results are robust to variations of the cooling time and the arrival time.

Introduction DSNB Motivations Theoretical Framework Results Simplified Model Conclusions

interaction as a pendulum

S. Hannestad, G. G. Raffelt, G. Sigl, and Y. Y. Y. Wong, Phys. Rev. 74, 105010 (2006), 0608695.

Inverted Hierarchy: with without

Nevents Detection window L S

19.3-30 MeV 0.078 (0.078) 0.089 (0.066)

9.3-25 MeV 0.211 (0.210) 0.224 (0.196)

Normal Hierarchy

Detection window L or S

19.3-30 MeV 0.066

9.3-25 MeV 0.196

Inverted Hierarchy: with without

Nevents Detection window L or S

17.5-41.5 MeV 0.059 (0.058)

4.5-41.5 MeV 0.099 (0.096)

Normal Hierarchy

Detection window L S

17.5-41.5 MeV 0.066 0.058

4.5-41.5 MeV 0.106 0.096


SHOCK

NO SHOCK

A simplified model to account for the shockwaveNO SHOCK

Nevents(without ) > Nevents(with )

A simplified model to account for the shockwaveSHOCK

A simplified model to account for the shockwaveSHOCK

Nevents(with ) increasesNevents(without ) decreases

Nevents(with ) Nevents(without )

Interval 0→ts ts→tp tp→t t→

With 0.5436 0.0634 0.3092 0.2548

Without 0.1611 0.6356 0.3531 0.4835

Times a0 a1 a2 a3 a4 a5

ts 1.02 10-2 1.72 10-1 -6.88 10-3 1.4 10-4 -1.2 10-6 4.2 10-9

tp 9.83 10-2 1.39 10-1 -2.47 10-3 4 10-5 -4.4 10-7 1.9 10-9

t 3.75 9.5 10-2 -5 10-4

This model can be used in future calculations of DSNB fluxes and rates to include shockwave effects.

Survival probability evolution with times and energy.



Evolution of times with energy.


BUT the luminosity decreasesSo we must do :


AND

AND

1. The interaction.

- J. T. Pantaleone, Phys. Rev. D 46 510 (1992).- S. Samuel, Phys. Rev. 48, 1462 (1993).- G. Sigl and G. G. Raffelt, Nucl. Phys. B 406 423 (1993).- Y. Z. Qian and G. M. Fuller, Phys. Rev. D 51 1479 (1995).- S. Pastor, G. G. Raffelt, and D. V. Semikoz, Phys. Rev. 65, 053011 (2002), 0109035.- H. Duan, G. M. Fuller, J. Carlson, and Y.-Z. Qian, Phys. Rev. 74, 105014 (2006), 0606616.- S. Hannestad, G. G. Raffelt, G. Sigl, and Y. Y. Y. Wong, Phys. Rev. 74, 105010 (2006), 0608695.- A. B. Balantekin and Y. Pehlivan, J. Phys. 34, 47 (2007), 0607527.- G. G. Raffelt and A. Y. Smirnov, Phys. Rev. 76, 125008 (2007), 0709.4641.- …

Recent developments in neutrino propagation in SN:

After the explosion of the star, the neutrinos density is so high that neutrinos interact each other giving rise to collective effects like synchronization, bipolar oscillations and spectral split.

Introduction

2. The shockwave effects.

- R. C. Schirato and G. M. Fuller (2002), 0205390.- C. Lunardini and A. Y. Smirnov, JCAP 0306, 009 (2003), 0302033.- K. Takahashi, K. Sato, H. E. Dalhed, and J. R. Wilson, Astropart. Phys. 20, 189 (2003), 0212195.- G. L. Fogli, E. Lisi, A. Mirizzi, and D. Montanino, Phys. Rev. 68, 033005 (2003), 0304056.- R. Tomas, M. Kachelrieß, G. Raffelt, A. Dighe, H.-T. Janka, and L. Scheck, JCAP 0409, 015 (2004), 0407132.- G. L. Fogli, E. Lisi, A. Mirizzi, and D. Montanino, JCAP 4, 2 (2005), 0412046.- S. Choubey, N. P. Harries, and G. G. Ross, Phys. Rev. D74, 053010 (2006), 0605255.- B. Dasgupta and A. Dighe, Phys. Rev. 75, 093002 (2007), 0510219.- S. Choubey, N. P. Harries, and G. G. Ross, Phys. Rev. 76, 073013 (2007), 0703092.- J. P. Kneller, G. C. McLaughlin, and J. Brockman, Phys. Rev. 77, 045023 (2008), 0705.3835.- J. P. Kneller and G. C. McLaughlin, Phys. Rev. 73, 056003 (2006), 0509356.- …

Introduction

The shock propagates through the matter in which it will modify the density profile and therefore the MSW resonance.

Introduction DSNB Motivations Theoretical Framework Results Conclusions

- …- I.K. Baldry and K. Glazebrook, Astrophys. J. 593, 258 (2003).- S. Ando and K. Sato, New Journal of Physics 6, 170 (2004), 0410061.- L. E. Strigari, J. F. Beacom, T. P. Walker and P. Zhang, JCAP 0504, 017 (2005), 0502150. - C. Lunardini, Astroparticle Physics 26, 190 (2006), 0509233.- H. Yüksel and J. F. Beacom, Phys. Rev. 76, 083007 (2007), 0702613.- S. Chakraborty, S. Choubey, B. Dasgupta, and K. Kar, JCAP 0809, 013 (2008), 08053131.- …

3. Progress on the Diffuse Supernova Neutrino Background (DSNB).

Introduction

There have been much progress on the ingredients of the DSNB such as star formation rate, initial mass function.

Normal Hierarchy Analytic (no shock) Numeric (shock)


17.5-41.5 MeV 0.074 0.066

4.5-41.5 MeV 0.116 0.106

Argon detectors.

Inverted Hierarchy: with Analytic (no shock) Numeric (shock)


19.3-30 MeV 0.066 0.078

9.3-25 MeV 0.196 0.211

Water Cerenkov and scintillator detectors. per kTon per year

DSNB event rates in -observatories

+18%

+8%

- 9%

-11%

• 10% variation only due to the presence of the shock.

Inverted Hierarchy: with + shock


19.3-30 MeV 0.078 0.089

9.3-25 MeV 0.211 0.224

Normal Hierarchy


17.5-41.5 MeV 0.066 0.058

4.5-41.5 MeV 0.106 0.096

Argon detectors.

per kTon per year


Water Cerenkov and scintillator detectors.

+14%

- 6%

-12%

• Same variation due to 13.• 10% variation only due to the presence of the shock.

Inverted Hierarchy: with + shock

Nevents Detection window L (with L (without

19.3-30 MeV 0.078 0.078

9.3-25 MeV 0.211 0.210

Normal Hierarchy

Nevents Detection window L

17.5-41.5 MeV 0.066

4.5-41.5 MeV 0.106

Argon detectors.

per kTon per year


Water Cerenkov and scintillator detectors.

• Loss of the sensitivity to collective effects in the L case.• Same variation due to 13.

+0%

+0%

• 10% variation only due to the presence of the shock.

The method usedWe use a 3 flavour code in which we solve the propagation of the amplitudes. We include the interaction (single angle approximation).

J. Gava, C. Volpe, Phys.Rev.D78:083007(2008), 0807.3418.

3. Spectral split.

This gives our at the supernova.

interactionInverted Hierarchy.

1. Synchronized region.

2. Bipolar oscillations.

MSW effect

DSNB Motivations Theoretical Framework Results Conclusions

sébastien galais s. galais, j. kneller, c. volpe and j. gava

Documents

simplified model

model conclusions neutrinos

model conclusions z

neutrino selfinteraction

relic neutrinos

main detection channel

shockwave impact

collapse supernova explosion99